// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter_web/material.dart';

import '../../gallery/demo.dart';

enum TabsDemoStyle { iconsAndText, iconsOnly, textOnly }

class _Page {
  const _Page({this.icon, this.text});
  final IconData icon;
  final String text;
}

const List<_Page> _allPages = <_Page>[
  _Page(icon: Icons.grade, text: 'TRIUMPH'),
  _Page(icon: Icons.playlist_add, text: 'NOTE'),
  _Page(icon: Icons.check_circle, text: 'SUCCESS'),
  _Page(icon: Icons.question_answer, text: 'OVERSTATE'),
  _Page(icon: Icons.sentiment_very_satisfied, text: 'SATISFACTION'),
  _Page(icon: Icons.camera, text: 'APERTURE'),
  _Page(icon: Icons.assignment_late, text: 'WE MUST'),
  _Page(icon: Icons.assignment_turned_in, text: 'WE CAN'),
  _Page(icon: Icons.group, text: 'ALL'),
  _Page(icon: Icons.block, text: 'EXCEPT'),
  _Page(icon: Icons.sentiment_very_dissatisfied, text: 'CRYING'),
  _Page(icon: Icons.error, text: 'MISTAKE'),
  _Page(icon: Icons.loop, text: 'TRYING'),
  _Page(icon: Icons.cake, text: 'CAKE'),
];

class ScrollableTabsDemo extends StatefulWidget {
  static const String routeName = '/material/scrollable-tabs';

  @override
  ScrollableTabsDemoState createState() => ScrollableTabsDemoState();
}

class ScrollableTabsDemoState extends State<ScrollableTabsDemo>
    with SingleTickerProviderStateMixin {
  TabController _controller;
  TabsDemoStyle _demoStyle = TabsDemoStyle.iconsAndText;
  bool _customIndicator = false;

  @override
  void initState() {
    super.initState();
    _controller = TabController(vsync: this, length: _allPages.length);
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  void changeDemoStyle(TabsDemoStyle style) {
    setState(() {
      _demoStyle = style;
    });
  }

  Decoration getIndicator() {
    if (!_customIndicator) return const UnderlineTabIndicator();

    switch (_demoStyle) {
      case TabsDemoStyle.iconsAndText:
        return ShapeDecoration(
          shape: const RoundedRectangleBorder(
                borderRadius: BorderRadius.all(Radius.circular(4.0)),
                side: BorderSide(
                  color: Colors.white24,
                  width: 2.0,
                ),
              ) +
              const RoundedRectangleBorder(
                borderRadius: BorderRadius.all(Radius.circular(4.0)),
                side: BorderSide(
                  color: Colors.transparent,
                  width: 4.0,
                ),
              ),
        );

      case TabsDemoStyle.iconsOnly:
        return ShapeDecoration(
          shape: const CircleBorder(
                side: BorderSide(
                  color: Colors.white24,
                  width: 4.0,
                ),
              ) +
              const CircleBorder(
                side: BorderSide(
                  color: Colors.transparent,
                  width: 4.0,
                ),
              ),
        );

      case TabsDemoStyle.textOnly:
        return ShapeDecoration(
          shape: const StadiumBorder(
                side: BorderSide(
                  color: Colors.white24,
                  width: 2.0,
                ),
              ) +
              const StadiumBorder(
                side: BorderSide(
                  color: Colors.transparent,
                  width: 4.0,
                ),
              ),
        );
    }
    return null;
  }

  @override
  Widget build(BuildContext context) {
    final Color iconColor = Theme.of(context).accentColor;
    return Scaffold(
      appBar: AppBar(
        title: const Text('Scrollable tabs'),
        actions: <Widget>[
          MaterialDemoDocumentationButton(ScrollableTabsDemo.routeName),
          IconButton(
            icon: const Icon(Icons.sentiment_very_satisfied),
            onPressed: () {
              setState(() {
                _customIndicator = !_customIndicator;
              });
            },
          ),
          PopupMenuButton<TabsDemoStyle>(
            onSelected: changeDemoStyle,
            itemBuilder: (BuildContext context) =>
                <PopupMenuItem<TabsDemoStyle>>[
                  const PopupMenuItem<TabsDemoStyle>(
                      value: TabsDemoStyle.iconsAndText,
                      child: Text('Icons and text')),
                  const PopupMenuItem<TabsDemoStyle>(
                      value: TabsDemoStyle.iconsOnly,
                      child: Text('Icons only')),
                  const PopupMenuItem<TabsDemoStyle>(
                      value: TabsDemoStyle.textOnly, child: Text('Text only')),
                ],
          ),
        ],
        bottom: TabBar(
          controller: _controller,
          isScrollable: true,
          indicator: getIndicator(),
          tabs: _allPages.map<Tab>((_Page page) {
            assert(_demoStyle != null);
            switch (_demoStyle) {
              case TabsDemoStyle.iconsAndText:
                return Tab(text: page.text, icon: Icon(page.icon));
              case TabsDemoStyle.iconsOnly:
                return Tab(icon: Icon(page.icon));
              case TabsDemoStyle.textOnly:
                return Tab(text: page.text);
            }
            return null;
          }).toList(),
        ),
      ),
      body: TabBarView(
          controller: _controller,
          children: _allPages.map<Widget>((_Page page) {
            return SafeArea(
              top: false,
              bottom: false,
              child: Container(
                key: ObjectKey(page.icon),
                padding: const EdgeInsets.all(12.0),
                child: Card(
                  child: Center(
                    child: Icon(
                      page.icon,
                      color: iconColor,
                      size: 128.0,
                      semanticLabel: 'Placeholder for ${page.text} tab',
                    ),
                  ),
                ),
              ),
            );
          }).toList()),
    );
  }
}
